The things that an LLM is likely to contain a complete verbatim copy of are things that are a) short b) widely repeated to the point that they're embedded into our culture - and by that token those things are almost certainly not copyrightable.
If you literally mean a bar, yes those are short, likely a couple of words, and you put those in books all the time and don't get sued. ("The answer my friend, is blowing in the wind" is 4 bars, and I've seen books quote it verbatim without a second thought). Likewise, plenty of people put the entire Declaration of Independence in their book without a second thought, and I assume don't get sued for it.
If you're talking about a verse or more of something that's not quite so culturally pervasive (people put the whole of the star-spangled banner in their books, again without a second thought), well, at that point it's probably not something that an LLM would reproduce verbatim.
